spamdyke -- open relay

Spamdyke Team reports:

Fixed smtp_filter() to reject the DATA command if no valid
recipients have been specified. Otherwise, a specific scenario could
result in every spamdyke installation being used as an open relay.
If the remote server connects and gives one or more recipients that
are rejected (for relaying or blacklisting), then gives the DATA
command, spamdyke will ignore all other commands, assuming that
message data is being transmitted. However, because all of the
recipients were rejected, qmail will reject the DATA command. From
that point on, the remote server can give as many recipients as it
likes and spamdyke will ignore them all – they will not be filtered
at all. After that, the remote server can give the DATA command and
send the actual message data. Because spamdyke is controlling
relaying, the RELAYCLIENT environment variable is set and qmail won’t
check for relaying either. Thanks to Mirko Buffoni for reporting
this one.